Without limiting the scope of the invention, its background is described in connection with polymeric encapsulation of compounds.
The encapsulation of pharmaceuticals and other compounds is of continuing interest, both in industry and in academia. Encapsulation may be used to modify the time-release properties of a material, to alter the solubility of a material and/or to provide other desirable property modifications. Polymers, biopolymers and peptides have been explored for their suitability as microencapsulation agents.
Microcapsules include, generally, a core material (liquid or solid) encased in a specialized coating. Microencapsulation technology has found widespread use in the pharmaceutical area, for example, coating of drugs to extend or delay their release or target their release to a specific area of the digestive tract. Other interesting applications include encapsulation of ink in carbonless carbon paper, encapsulation of perfumes in ‘scratch and sniff’ types of promotionals and encapsulation of living pancreatic cells to treat diabetes. In the case of living cells, the pore size of the microcapsule is selected to prevent the passage of host antibodies while allowing the free exchange of insulin and glucagon. Microcapsules have also found application in the food, cleaning, adhesives, fertilizers and aerospace industries to name a few.
Albumin has been used in the preparation of microcapsules. Two technologies have been used—coacervation, or oil in water emulsions. These techniques have been the source of many publications, including Zimmer et al. (J. Controlled Release 33: 31-46 (1995)); Cremers et al. (Biomaterials 15(1): 38-48 (1994)); Deasy (Microencapsulation and Related Drug Processes; Marcel Dekker, Inc., NY (1984)); and Tomlinson, E. and Burger, J. J. Methods Enzymol. 112: 27-43 (1985)). Despite the efforts made towards developing microencapsulation methods, there still exists a need for novel and effective materials for the encapsulation of various materials.